Diastereoselective Hydrogenation of Substituted Quinolines to Enantiomerically Pure Decahydroquinolines

作者：Heitbaum Maja; Froehlich Roland; Glorius Frank^*

来源：Advanced Synthesis & Catalysis, 2010, 352(2-3): 357-362.

DOI：10.1002/adsc.200900763

• asymmetric synthesis
• chiral auxiliaries
• decahydroquinolines
• heterocycles
• hydrogenation

The stereoselective hydrogenation of auxiliary-substituted quinolines was used to build up saturated and partially saturated heterocycles. In a first step, the formation and diastereoselective hydrogenation of 2-oxazolidinone-substituted quinolines to 5,6,7,8-tetrahydroquinolines is reported. In this unprecedented process, stereocenters on the carbocyclic quinoline ring were formed with a dr of up to 89:11. Platinum oxide as a catalyst and trifluoroacetic acid as a solvent were found to be optimal for high levels of chemo- and stereoselectivity in this step. In a second hydrogenation step, the completely saturated decahydroquinolines with 4 newly formed stereocenters were obtained with enantioselectivities of up to 99%. Rhodium on carbon as a catalyst and acetic acid as a solvent gave the best results for this hydrogenation and allowed a traceless cleavage of the chiral auxiliary. Thus, this new method allows an efficient stereoselective synthesis of valuable 5,6.7,8-tetrahydro- and decahydroquinoline products.

• 出版日期2010-2